This application relates to a capacitor and, more particularly, to a multilayer capacitor.
Capacitors are used in integrated circuit systems for a variety of functions including power decoupling, noise filtering, and resonance damping. Power decoupling assists in preventing a drop in voltage levels at input/output terminals of an integrated circuit die. Sudden increased power demands of the die can cause a drop in voltage levels at the die terminals. This voltage drop on the die increases the switching time of the transistors on the die, which degrades the performance of the system fabricated on the die. Typically, discrete decoupling capacitors are mounted adjacent to the die and connected to the conductors that provide power to the die. For a processor die, the die is mounted on a substrate, and a ring of capacitors, usually ten to fifteen two microfarad capacitors, are mounted on the substrate along the periphery of the die. These capacitors are coupled to the power supply connections at the die through lands formed on the substrate. However, there are problems associated with such power decoupling. For example, a large number of capacitors may be required to adequately control the voltage drop. A large number of capacitors consumes valuable real estate on a substrate. Further adding longer leads from the power supply to the die terminals to accommodate the capacitors increases inductance and resistance, which hampers the prevention of voltage drop and limits power decoupling at higher frequencies.
For these and other reasons there is a need for the present invention.